Collapsible tap or die.



R. C. LEWIS.

COLLAPSIBLE TAP OR DIE.

APPLICATION FILED NOV. 16. ISIS.

l 263,884. Patented Nov. 7', 1916.

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W K A/Iomqs R. C. LEWIS.

COLLAPSIBLE TAP OR DIE.

APPLICATION FILED NOV. 16. 1915.

1 ,203 884. Patented Nov. 7, 1916.

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APPLECATION FILED NOV. 16. 19w.

Patented Nova 7, 1916.

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W/TNE SE5 a) M Cir UNITED srarrns PATENT @FFKCE.

ROLLIN C. LEWIS, OF STAMFORDJCONNECTIGUT, ASSIG'NOR TO THE YALE & TOWNE MANUFACTURING COMPANY, OF STAMFORD, CONNECTICUT.

COLLAPSIBLE TAP OR DIE.

Application filed November 16, 1915.

To all whom it may concern:

Be it known that I, Forma 0. LEWIS, a citizen of the United States, and a resident of Stamford, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Collapsible Taps or Dies; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improvement in a collapsible tap or die designed more particularly for use in a turret lathe, or in a machine wherein the article or work to be tapped or threaded usually revolves, and the tap or die as the case may be is forced toward the article without rotary movement, the article to be threaded being held in a revolving chuck.

The object of my invention is to provide improved means by which the parts after cutting the thread the desired depth, are immediately withdrawn from engagement with the article or work being threaded and pulled back into position to be reset for repeating the operation.

Another object is to provide improved adjusting means, whereby the chaser or cutting parts may be accurately adjusted, so as to produce very accurate results in cutting threads, and at the same time be rigidly backed up by the body of the tool so the chasers will not be distorted in the act of cutting.

A further object is to provide means whereby the life of the chasers is lengthened by the provision whereby a large part of the periphery of the chasers can be used for producing new cutting edges by re-sharpening, and by the further provision of adjusting means whereby the re-sharpened cutting edges may be repeatedly brought into proper relation with the periphery of the tool.

lVith these ends in view my invention consists in the parts and combination of parts as will be more fully explained and pointed out inthe claims.

In the accompanying drawings Figure 1 is a view in elevation of my improvement. Fig. 2 is an end view of the same. Fig. 3 is a view in section on the line AA of Fig. 2. Fig. t is a similar view on the line B-B 0 Fig. 2-

5 is a view of: the body tic Specification of Letters Patent.

Patented Nov. *7, 1916.

Serial No. 61,809.

t pol showing the adjusting wedge thereon. a 1g. 6 is a view of the cap. Fig. 7 is a new of the chasers actuating gear and its operating handle. Fig. 8 is a view of the shank. Fig. 9 is a view of one of the chasers. Fig. 10 is a view of the sectional disk for locking the chasers in place. Fig. 11 is a view of the releasing wedge, and Figs. 12, 13 and 1a are views of a modification.

1 represents the shank of the tool adapted for attachment to a turret head or other fixture of any desired machine tool. This shank is provided with a head 2 threaded externally for the attachment of the body of the tool, and is also provided on its end with a counterbored recess 3 for the recep tion of the ends of the chasers or cutters. and for the sectional disk 5 which locks the chasers or cutters in place. These chasers or cutters are hereinafter referred to as chasers. The body 6 is cylindrical in shape, and preferably of two diameters as shown, the outer portion of the body being preferably a solid block with a plurality of holes there through for the chasers 4, located equiois tant apart, and the inner end thereof is made hollow to receive the annular gear wheel 7 and front end of the head 2 of shank 1, the free end of the hollowed part of the body icing internally threaded to engage the external threads on said head 2.

In the drawings, I have shown four chasers, but the number is immaterial. They are provided with the usual or any preferred form of cutting edge, and each is provided adjacent its inner end with a peripheral groove 8 in which the sectional disk 5 rests, and with the peripheral teeth 10 which are engaged bv the internal teeth on the gear wheel 7. The chasers r are so located and arranged that the teeth 10 on each are engaged by the internal teeth of gear wheel 7, so that when wheel 7 is turned, as will be hereinafter explained the chasers will be given a part rotation simultaneously.

The disk 5 which secures the chasers in place is made in section, as shown in Fig. 10. If there be four chasers, the disk should be in four sections so as to permit it to be applied to the chasers after the latter have been placed in the body of the tool. Each section of the disk is provided with curved bearings 11 which enter the grooves 8 in the chasers and lock the latter in place. The extreme of the shasers rest the counterbore 3, in the end of the head 2 of the shank, while the disk 5 rests in the bore '3 and is held in place against the head 2,

by the gear wheel 7 which is located within the body of the tool, between the shoulder 12 and front end of the head 2. This gear wheel is provided with a handle 7 integral with or fixed to the wheel, and with a shield 7 which closes the opening in the body through which the handle 7 passes, the said shield being secured to the handle at a point outside of the body as shown in Fig. 2. The handle 7 a of the gear wheel also carries the latch 13, which is pivoted to the handle and normally held with its free end in contact with the body of the tool, by the spring let secured to the handle and adapted to abut at its free end against the latch 13. The gear wheel 7 is provided with a peripheral semi-circular groove 7 c which alines with a semi-circular groove in the body 6, for the reception of a spiral spring 15, one end of which bears against a shoulder onthe gear wheel 7 while the opposite end bears against an abutment rigid with the body 6 of the tool. The tendency of this spring is to rotate the gear wheel 7 in a direction to turn all the chasers 4 sufiiciently to present the flat side of the cutting ends to the periphery of the tool, thus disengaging the cutting edges from the threads cut in the work and freeing the tool so that it may be removed at once.

At the start of the operation the spring 15 is put under tension by turning the handle 7 against the pressure of the spring. This movement of the handle turns the gear wheel 7 and the latter in turn rotates all the chasers sufi'iciently to bring their cutting edges in proper relation to the work, and the parts are so held by the latch 13, the free end of which bears against the projecting edge of the adjustable wedge 9. This wedge has one straight edge and an inclined edge, the latter bearing against the similarly inclined abutment or shoulder 16 rigid with the body 6, and is secured in place'by a screw 17 passing through an inclined slot in the wedge. This wedge 9 bears at its rear end against the knurled ring 9, which acts as a stop for the wedge in the event the screw 17 should become loose. This ring 9 is screwed onto the threaded end of the head 2 and is designed to be adjusted thereon so as to form an adjustable stop for the wedge.

In the ordinary operation of the tool, in order to adjust it for proper depth of cut, or for a tighter or looser fit, it is necessary to bring the cutting edges of the chasers nearer to or farther away from the periphery of the tool. This is accomplished by means of the adjustable wedge 9. Then this wedge is pushed toward the outer end or the tool, it moves against the fixed abutment 16 and is moved laterally thus moving the latch 13 and the handle 7 to which the latch is attached, sidewise, which movement partly rotates the wheel 7 a distance sufficient to efiect the proper adjustment of the cutting edges of the chasers. When the wedge has been moved its full distance, and all the adjustment of which it is capable has been taken advantage of, further adjustment may be provided for by taking the tool apart, turning the chasers one tooth in their engagement with the gear wheel 7, and moving the wedge back to its rearward position. This starts the mechanism over from a new point, and it may be adjusted as before by moving the wedge downward or away from the outer end of the tool as may be necessary.

The chasers are cylindrical and they are provided with threads which extend nearly around their entire periphery. The chasers are also provided at their inner ends with teeth, which in connection with the adjusting mechanism elsewhere described, enable the chasers to be adjusted around nearly an entire circle. This construction permits the cutting edge, when it is worn, to be reground, and the re-ground edge can then be brought to exactly the proper point for cutting the desired thread. Thus nearly the whole of the periphery of the chasers can be utilized, thus tending to economy in material and in time required to keep the tool in operative condition.

Secured over the outer end of the body is the cap 19. This cap has an open center for the passage of the chasers 4, and is locked against displacement by a screw 20 secured to the body 6 and passing through an elongated slot 21 in the cap, the slot being of a length sufiicient to permit of the necessary movement of the cap. Mounted in recesses in the outer end of the body are a series of spring pressed plungers 22 which bear against the inner face of the cap and normally tend to push the same outwardly, the said cap being in a position to be engaged by the work being tapped or threaded. Secured to the side of the cap is the releasing wedge 23 shown detached in Fig. 11. This releasing wedge projects under the latch 13 of the handle 7, and as it is moved rearwardly as the work progresses by the rearward movement of the cap 19, it operates to move the latch outwardly so as to disengage it from the adjusting wedge 9, thus leaving the handle 7 and its gear wheel 7 free to be rotated by the spring 15 sufliciently to turn the flat sides of the chasers outwardly. This rotation of the chasers disengages the cutting edges from the threads in the work and leaves the tool free to be removed.

The method of assembling the tool is as follows: The handle 7 of the gear wheel is passed upwardly into the hollow end of the body and out through the opening in t'he side of the latter, thus carrying the gear into its proper position in the bottom of the body. The chasers are then inserted in the holes and properly meshed with the teeth of the gear, after which the sections of the disk 5 are placed around the chasers so as to lock the latter in place. The head of the shank is then screwed into the open end of the body thus looking all the parts in place.

In the modification shown in Figs. 12, 13 and 14, I have shown means for adjusting the sections of the chasers holding disk, whereby the chasers may be removed without taking the tool apart, and also a modifi cation of the means for releasing the latch to disengage the chasers from the work.

In the construction above described the disk sections are placed in position before the body and shank are secured together, and when it becomes necessary to take out the chasers for grinding or any other purpose, the tool has to be disassembled. In the modified construction the disk sections are inserted in substantially the same manner as before, but the body of the tool is so constructed that the disk sections may be moved toward the periphery of the body sufiiciently to disengage themselves from the groove bearings in the chasers. Each disk section 5 is provided at its outer edge with a projection 5 which when the disk sections are in their normal position and in engagement with the chasers, rests approximately flush with surface of the body and are held there by screws 5. By removing the screws and pulling outwardly on the projection 5", the sections of the disk will be drawn outwardly sufficiently to disengage the chasers thus leaving the latter free to be rem ved for regrinding, re-adjustment, or any other purpose which necessitates their removal.

In the modified form I have also omitted the cap 19 of the previous construction, and substituted :1- plunger Q l mounted centrally within the body between the chasers, and normally projecting beyond the same so as to engage the work and be moved rearwardly thereby. This plunger is normally held outwardly by a spring 25 located within the shank of the tool, and is provided with an inclined or cam surface 26 adapted when the plunger is moved rearwardly, to engage the inner end of slide '27. the outer end of which rests under the latch 13, and which is moved longitudinally by said cam surface 26 and operates to force the latch outwardly and disengage it from the adjusting wedge, thus leaving the spring 15 free to turn the gear and chasers as previously explained. lVith this and also the modified improvement shown, the chasers can be accurately adjust ed to cut to the size and depth desired. and the arrangement is such that the cutting edge revoives around centers equiclistant from the periphery of the tool so that all parts of the edges, when the chasers are revolved, bear the same relation to the leriphery of the tool, thus prolonging the life of the chasers.

While 1 have shown and described my improvement as applied to tools for tapping or internal threading, it is clearly evident that by a rearrangement of the chasers and the operating handle the device can be used as a die for external threading.

It is also evident that various changes in the details may be resorted to without departing from the spirit of my invention hence I would have it understood that I do not limit myself to the details shown but consider myself at liberty to make such changes and alterations as may come within the spirit of the invention expressed in the claims.

Having fully described my invention what I claim as new and desire to secure by Letters-Patent, is:

1. In a tool for forming screw threads, the combination of a body, a plurality of chasers carried by said body and located equidistant from the periphery thereof, each chaser being cylindrical in form and having a cutting edge and a flat face adjacent the cutting edge, a gear wheel fixed against movement parallel to the long axis of the tool and meshing with teeth on the series of chasers for turning them simultaneously in the same direction, a spring normally tending to turn said gear wheel, means for holding the wheel against the tension of the spring, and means for releasing the wheel holding means.

2. In a tool for forming screw" threads, the combination of a body, a plurality of chasers carried by said body, a gear wheel meshing with teeth on the chasers for rotating all of the chasers simultaneously in the same direction, the said gear wheel being fixed against movement parallel to the long axis of the tool, means for holding the gear against rotary movement, and means actuated by contact with the work being screw threaded to release said holding means, thus permitting the gear to turn the several. chasers in a direction to disengage them from the work.

3. In a tool for forming screw threads. the combination of a bot y, a plurality of chasers carried thereby, each having a peripheral groo e at its inner end. holdi 2; means engaging; the grooves in the chasers for locking them in the body. a gear wheel fixed against movement in the direction of the long axis of the tool and engaging teeth on the several chasers for rotating the latter simultaneously, and means for rv'atating said gear wheel.

4. In a tool for forming screw threa s. the combination of a body, a series of chasers mounted to rotate in said body and projecting at one end from the latter, each chaser having a peripheral groove at its inner end, a sectional disk engaging the peripheral grooves in the chasers. for locking them to the body, and means for turning the chasers.

'5. In a tool for forming screw threads, the combination of a body, a series of chasers mounted to rotate in said body, each chaser having a peripheral groove at its inner end, a sectional disk engaging the said grooves for locking the chasers to the body of the tool, the said disk sections adapted to be movedtoward and away from the periphery of the body for releasing and locking the chasers, and means for rotating the latter.

'6. In a tool for forming screw threads, the combination of a body, a series of chasers mounted to rotate in said body, each chaser having a peripheral groove at its inner end, a sectional disk within the body and engaging said grooves for locking the chasers in place, the said disk sections adapted to be moved toward and away from the periphery of the body for releasing and looking the chasers, and means for locking the disk sections against movement.

7. In a tool for forming screw threads, the combination of a body, a series of chasers mounted to rotate in said body, each chaser having gear teeth adjacent its inner end, a gear wheel mounted to rotate in said body and having internal teeth engaging the teeth on the chasers, the said gear wheel being fixed against movement in the direction of the long axis of the tool, a spring for rotating the gear wheel, a latch for holding the gear wheel against the tension of the spring, and means actuated by contact with the work being threaded for disengaging the latch thus permitting the spring to ro tate the gear Wheel.

8. In a tool for forming screw threads, the combination of a body, a series of chasers mounted to rotate in said body, each chaser having gear teeth adjacent its inner end, a gear wheel mounted to rotate in said body and having internal teeth engaging the teeth on the chasers, a spring for rotating the gear wheel, a latch for holding the gear wheel against the tension of the spring, an adjustable shoulder against which said latch bears, means projecting beyond the end of the body and adapted to engage the work, and means actuated by said projecting means for-disengaging the latch from the shoulder,

thus permitting the spring to rotate the gear wheel.

9. In a tool for iorming screw threads, the combination of a body, a series of chasers mounted to rotate in said body, each chaser having gear teeth adjacent its inner end, a gear wheel mounted to rotate in said body and having teeth engaging the teeth on .the chasers, a spring for rotating the gear wheel, a wedge adjustably secured to the outside of the tool, a latch carried by said gear wheel and adapted to engage the wedge for holding the gear wheel against the tension of the spring, and means actuated by contact with an abutment independent of the tool for disengaging the latch from the wedge thus permitting the spring to rotate the gear wheel.

10. In a tool for forming screw threads, the combination of a body, a series of chasers mounted to rotate in said body, each chaser having gear teeth adjacent its inner end, a gear wheel mounted to rotate in said body, the teeth of said wheel engaging the teeth on the chasers, a spring for rotating the gear wheel, an adjustable abutment secured to the outer face of the body, a latch carried by the gear wheel and adapted to engage the said abutment for holding the gear wheel against the tension of the spring, a sliding device adapted to engage the latch for disconnecting the same from the abutment, thus permitting the spring to rotate the gear wheel, and means adapted to contact with a stop independent of the tool for actuating the sliding device.

11. In a tool for forming screw threads, the combination of a body, a series of chasers mounted to rotate in said body, each chaser having gear teeth adjacent its inner end, a gear wheel mounted to rotate in said body, the teeth of said wheel engaging the teeth of the chasers, a spring for rotating the gear wheel, an abutment on the outer face of the body, a latch carried by the gear wheel and adapted to 'engagethe abutment for holding the gear wheel against the tension of the spring, a sliding device adapted to engage the latch for disconnecting it from the abutment, thus permitting the spring to rotate the gear wheel, and yielding means carried by the body of the tool and projecting beyond the front end or" the latter for actuatingsaid sliding device.

12. In a too-l for forming screw threads, the combination of a body having a series of openings longitudinally thereof, the said body being recessed at its rear end, a series of chasers 'mountedin said openings and projecting into the recess, each chaser having a toothed inner end, a gear wheel mounted in said recess the teeth of the gear wheel meshing with the teeth on the chasers, means for locking the chasers against displacement, a spring for rotating the gear wheel, means for holding the gear wheel against the rotation of the spring. means for automatically releasing said holding means, and a shank secured in the rear end of the tool and closing the recess in the latter.

13. In .a tool for forming screw threads, the combinationof a body having a series of openings therein for the chasers, a chaser in each opening, the said chasers being removable endwise through the outer end 01": the body, a gear wheel meshing with teeth on the several chasers for turning them simultaneously and a sectional disk engaging the several chasers at their inner ends for holding them against endwise displacement.

14. In a tool for forming screw threads, the combination of a body having a. series of openings therein, each of a size to admit a chaser endwise, a chaser in each opening, a

' gear wheel within said body and meshing with teeth on the several chasers whereby the latter will be simultaneously rotated, a spring tending to turn the wheel; means for holding said wheel against the tension of the spring, means for dislodging said holding means so as to permit the spring to turn the gear wheel and a sectional disk within the body of the tool and engaging the chaser to hold them against endwise movement.

15. In a toolfor forming screw threads, the combination of a body, a series of chasers mounted to turn therein, an adjusting wheel adapted to actuate said chascrs by simultaneously turning them, and a wedge adjustably secured to the said body so that the movement of said wedge moves said adjusting wheel whereby the chasers may be adjusted for different depths of cut.

16. In a tool for forming screw threads, the combination of a body carrying a series of chasers, a gear wheel carried by said body and meshing with teeth on the several chasers, adjustable means for engaging the several chasers near their inner ends for holding them against endwise displacement, and an adjustable wedge carried by said body and adapted to move and adjust said gear wheel.

I11 testimony whereof, I have signed this specification in the presence of two subscribing witnesses.

- ROLLIN G. LEIVIS.

Witnesses SCHUYLER Mnnnrr'r, STUART B. AVERY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

